This was Television on February 21

2005: Avatar: The Last Airbender debuts

The animated adventure series—set in a world where select individuals called “benders,” command the elements of earth, wind, water, and fire—began a three season run on Nickelodeon. The show centered on the adolescent Avatar, a uniquely powerful bender, and his friends as they attempted to save the world from a conquering empire. Consistently well-rated and critically appreciated, Avatar spawned a series of comic book extensions, a spin-off series in The Legend of Korra, and a live-action film adaptation which is best forgotten. -A.D.